Building it cold.
The most common mistake is writing the file before you have refined the prompt. You will guess at what the job needs and guess wrong. Do the job by hand first.
PLAYBOOK · 03 · WRITING YOUR FIRST SKILL · BY MARC KLEINMANN
A skill is one job, written down once, so it runs the same way every time.
How to build your first Claude skill, the right way. Start with the prompt, not the file. The five steps every skill follows, a blank skeleton you can copy, and the real weekly client update I run, filled in. Written for the operator who keeps re-explaining the same job.
01 ·Context
A skill is one job, written down once, so the AI runs it the same way every time.
The shape of your weekly client update. The way you size up a new lead. The five things you check every Monday before coffee. Write it down once and you stop re-explaining it.
The one rule that matters: do not start by writing the skill. Most people hear the word, get excited, and try to build one cold. Wrong order. You write a careful file for a job you do not understand yet, and it is wrong in ways you cannot see.
Start with the prompt instead. Do the job the slow way. Type out what you want, in plain words, every time you do it. Next time, fix the part that came out wrong. The week after, tighten it again. You start saving the good version and pasting it back in, because retyping it is annoying. That annoyance is the signal. When you would happily paste the same prompt every time, that is the moment to write the skill. It is just that refined prompt, given a name and a home in a file.
02 ·Architecture
The five steps every skill follows.
Every skill I run has the same five steps. None of them are technical.
Step 01 · Check the scopeAsk what to leave out or lead with.
If you say "just draft it," it uses the defaults and skips ahead.
Step 02 · GatherPull the inputs from wherever they live.
So you do not open five tabs.
Step 03 · Compose in your voiceLoad your writing rules before it writes a line.
So the draft sounds like you.
Step 04 · Check its own workRun pass-or-fail checks first.
And do not show the draft until they all pass.
Step 05 · Stop. Draft only.Write the draft, flag the lines that need your eyes, hand it over.
It does not send.
03 ·Setup
Where this file goes.
The same skill body works across all three tools.
In ClaudeSave it as a SKILL.md file.
This is a skill. Save it as a file named SKILL.md in a skill folder. If you are not using skill files yet, paste the body into a Project's instructions and trigger it by name.
In ChatGPTPaste it into a Project or a custom GPT.
Paste the body into a Project's instructions, or into a custom GPT.
In GeminiPaste it into a Gem.
Paste the body into a Gem.
04 ·Decisions
Three calls you make when you build one.
Decision 01Refine the prompt first, or write the skill now.
Always refine first. The skill is the refined prompt with a name. You earn it by doing the job enough times to know exactly what it needs.
Decision 02Draft, or send.
Always draft. You do not hand a client relationship to software. A good skill is built so you never have to.
Decision 03Build it yourself, or hire it out.
You do not need to write the file yourself. You need to be able to say: here is a job I do every week, here are the places the information lives, here is how I want it to sound, and I want a draft, not a send. That sentence is a spec. Any competent builder turns it into a skill.
05 ·Runbook
The skeleton, blank and filled in.
Start from the blank skeleton. Do the job by hand as a plain prompt first, then fill one blank at a time.
SKILL.md · blank skeleton
--- name: your-skill-name description: One line that says what this skill produces, where it pulls from, and that it stops at a draft. This sentence is what tells the AI when to run it, so be specific. --- # Name the job this skill does Purpose: one or two sentences. The recurring job you got tired of re-explaining. Draft only. You review and send. ## Before you fill this in Do the job by hand as a plain prompt first. Run it a few times. Fix one thing each time until you would happily paste the same prompt every week. Only then fill in the steps below. If you are not there yet, stop and keep refining the prompt. ## Step 1: Check the scope Note: ask me what to leave out or lead with this time. If I say "just draft it," use the defaults and skip ahead. FILL IN: the one scope question you want it to ask first. ## Step 2: Gather Note: pull the inputs from wherever they live, so I do not have to open five tabs. FILL IN: the exact places to read. Which files, folders, inboxes, tools, or notes. ## Step 3: Compose in my voice Note: load my writing rules before writing a single line, so the draft sounds like me and not a chatbot. FILL IN: where your voice or writing rules live, and the structure the output should follow. ## Step 4: Check your own work Note: run pass-or-fail checks and do not show me the draft until they all pass. FILL IN: your checks. A good default: no em dashes, nothing duplicated, and nothing meant for one person ends up in another's. Make that last one a hard stop. ## Step 5: Stop. Draft only. Note: write the draft, flag the two or three lines that need my eyes, and hand it over. Do not send. FILL IN: where the draft gets saved. Confirm it never sends on its own.
Now the same skeleton, filled in. This is the real skill I run every week. My weekly client update, after I had done it by hand enough times to know every step.
SKILL.md · weekly client update
--- name: weekly-client-update description: Draft my weekly status update to a client. Pulls project status, open tasks, and the last week of our shared messages and meeting notes, then writes the draft in my voice. Draft only. I review and send. --- # Weekly client update Purpose: every week I owe a client a status update. What shipped, what I need from them, what is coming. This skill does the gathering and the first draft. I keep the judgment and the send button. ## Before I built this I wrote this update by hand for weeks and kept refining the prompt until it came out the same every time. Only then did I save it here as a skill. ## Step 1: Check the scope Ask me three things before writing. Any project to leave out this week? Anything to lead with or bury? Normal weekly, or a shorter mid-week check-in? If I say "just draft it," skip the questions and use the defaults. ## Step 2: Gather Read, in this order: - The current status of every project for this client. - My task list, filtered to tasks with this client's name on them, plus anything finished in the last seven days. - The last seven days of our shared Slack channel and DM, and any email threads with this client. - My meeting notes from any meeting in the last seven days where this client was present. Pull out decisions they made, commitments I made, and what each of us is waiting on from the other. ## Step 3: Compose in my voice Load my writing rules before composing a single line. Structure the draft this way: one-line opening, what shipped, what I need from you, what is in flight, what is coming next week. Lead with the client's world, not my activity. "Your migration shipped Friday" beats "I worked on the migration." Use specifics, not adjectives. Skip any project that does not need their attention this week. ## Step 4: Check your own work Run these pass-or-fail checks. Do not show me the draft until they all pass. - No em dashes. - No project listed in two sections. - One sentence per bullet. - The hard stop: nothing meant for another client appears in this update. If anything crossed over, cut it and flag it. ## Step 5: Stop. Draft only. Save the draft as a file named for the client and the date. Flag the two or three lines that need my eyes before I send. Do not send. I read, I fix, I send it myself.
Read the two boxes next to each other and the mapping is obvious. Each blank became one concrete instruction. Swap in your own client, your own places, your own voice file, and it is yours.
06 ·Gotchas
The three that catch everyone.
No self-check.
A skill without Step 4 will hand you a draft with a client's name in the wrong update. The cross-client check is the one that matters most. Make it a hard stop.
Automating the send.
The moment a skill sends on its own, you have given away the judgment call. Keep the send button.
07 ·What's next
What happens when you have a few.
One skill saves you a half hour. The interesting part is what happens when you have a few.